采用自零拍探测法和分析腔转换法,分别对适用于音频段压缩态光场制备的全固态单频激光器和光纤激光器的正交分量噪声进行了对比分析。结果表明,1064 nm全固态单频激光器的正交振幅噪声和正交相位噪声分别在分析频率大于1.5 MHz和5 MHz之后即达到散粒噪声基准,光纤激光器在测量带宽范围内均高于散粒噪声基准。采用半导体放大器(SOA) 降噪系统后,光纤激光器的低频段(<620 kHz)正交振幅噪声小于全固态单频激光器。本研究结果为低频段压缩态光场的研究提供了单频光源选择方案;SOA降噪系统可有效抑制低频段激光的正交分量噪声,为音频段压缩态光场的制备提供了依据。

This study uses the self-homodyne detection and analysis cavity conversion method to compare the quadrature component noises of all-solid-state single-frequency laser and fiber laser suitable for the preparation of the squeezed-state light field in audio-band frequencies. The results show that the quadrature amplitude and quadrature phase noises of the all-solid-state, single-frequency, 1064 nm laser reach the shot-noise limitation after analysis frequencies of 1.5 MHz and 5 MHz, respectively. Moreover, the measurement bandwidth of the fiber laser is higher than that of the shot-noise limitation. With the semiconductor optical amplifier (SOA) noise-reduction system, the low-frequency-bandwidth (<620 kHz) quadrature amplitude noise of the fiber laser is smaller than that of the all-solid-state single-frequency laser. This result provides a single-frequency source-selection scheme for the study of the low-frequency-bandwidth squeezed-state light field. The SOA noise-reduction system can effectively suppress the quadrature component noise of the low-frequency-bandwidth laser and provide an evidence for the preparation of the squeezed-state light field in audio-band frequencies.